Ответ:

В предложениях с конкретным завершённым временем используется Past Simple, а при связи действия с настоящим, опыте или периоде, который продолжается до настоящего момента, — Present Perfect.

  1. He has lost his keys. Now he can’t open the door!
  2. They didn’t meet each other last week.
  3. I have known her for five years.
  4. She bought a new dress last Monday.
  5. Have you ever tried sushi?
  6. We moved to a new house last month.
  7. The train has already left.
  8. He wrote this letter when he was 10.

Ответ: 1) has lost; 2) didn’t meet; 3) have known; 4) bought; 5) Have ... ever tried; 6) moved; 7) has already left; 8) wrote.